Gram Positive Bacilli
Elek's gel precipitation test is done for:
|B||Salmonella cholerae suis`|
a. Elek’s gel precipitation test is an in-vitro toxigenicity test for C.diphtheriae
b. It is an immunodiffusion test used to detect toxin production by strains of Corynebacteria.
c. A strip of filter paper impregnated with diphtheria antitoxin is placed on the surface of serum agar. The organism is streaked at right angels to the filter paper. Incubate the plate at 37C for 24 hrs.
d. After 48 hrs incubation, the antitoxin diffusing from filter paper strip and the toxigenic strains produce exotoxin, which diffuses and result in precipitation lines radiating from intersection of the strip and the growth of organism.